For demand response, metering, frequency monitoring, fault detection, and/or power quality measurements, the voltage and current of a wire are detected. For example, energy and power information is used to optimize energy costs. As another example, energy and power information is used in demand response scenarios to support aggregated demand response functionality.
For current measurement of a powered wire (e.g., “hot” mains power into a facility), the magnetic field is measured by a current transformer. The sensor is simply placed around the wire. Placing the sensors for performing the voltage measurements may be more difficult. For voltage measurement of the powered wire, a metal-to-metal or physical connection of the voltage meter feed to the wire is created using a bare wire, ring lug connector, wire nuts, or a screw down. Since the wire is powered during the connection, the installer must be careful. In some situations, the measurements are temporary, such as for analysis. Removing sensors after the analysis incurs a cost.